Flash Storage – 10 Essential Flash Must Have Checklist
We provide Flash Storage solutions for a wide variety of applications and operating systems.
Flash Storage Uses
Any organisation today should at least have Flash storage on their radar. Five years ago this wouldn’t be worth doing unless you had an enormous budget or needed to solve some super complicated task quickly. The price of flash has tumbled and will continue to do so for the foreseeable future, but as the price comes down the capacity goes up.
The Flash storage systems we provide are designed to work virtualisation technologies VMware, Hyper-V, Citrix, VDI as well as storage for Video, CCTV, Post Production, D2D, backup/archiving, The Cloud, Data-centres and many other applications.
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If your thinking about traditional disk storage, also think of this as a Flash storage opportunity.
The differing types of flash storage
All of the systems below contain flash storage in one form or another.
- Hybrid Storage – Designed as an intermediary between spinning disks and flash. Introduced over 5 years ago, these were the first storage platforms to take advantage of flash, could provide significant performance improvements, albeit at far less cost than an All-Flash Array.
- SSD Storage – Based on 2.5″ SSD drives, these are primarily designed to replace 1 or 2 drives in an existing disk sub-system to enhance performance. The issue is that a normal RAID storage system cannot handle the massive performance SSD’s provide, basically they overwhelm the data bus. So there is little or no point in replacing 16x spinning disk with SSD as it probably won’t be able to handle it.
- PCIe Storage – Now flash operates at the speed of the bus rather than the SAS/SATA controller. The primary issue with PCIe is the number of controllers that can handle the extra bus speed and the lack of standard compatibility between storage vendors which could cause interoperability issues. Overtime these issues will all be incorporated in future versions of PCIe, but for now it’s a path that hasn’t been tried, tested or approved by standards committees.
- NVMe Flash – NVMe is a high-performance, NUMA (Non Uniform Memory Access) optimised, and highly scalable storage protocol, that connects the host to the memory subsystem. The protocol is relatively new, feature-rich, and designed from the ground up for non-volatile memory media (NAND and Persistent Memory) directly connected to CPU via PCIe interface. The protocol is built on high speed PCIe lanes. PCIe Gen 3.0 link can offer transfer speed more than 2x than that of SATA interface.
- All Flash Storage – Designed to take full advantage of SSD drive technology, allied to high speed controllers, advanced data analytics and a relatively future proof upgrade path, these systems are designed to provide the simplest and easiest out of box uses with a number of host interfaces allowing you to connect and go.
Flash Cell Types
Most of today’s storage arrays use Non-volatile NAND flash memory which is supplied as SSD drives. There are now four types of NAND and these are single-level cell (SLC), multi-level cell (MLC) or triple-level cell (TLC) technology and now finally quad-level cell (QLC). SLC stores one-bit-per cell, has longer endurance, but is significantly more costly to produce with higher capacities. MLC uses two bits per cell and TLC uses three bits per cell and QLC uses four bits per cell. The TLC & QLC flash technologies have lower endurance, but hold larger capacities and can be produced at lower costs.
Flash stores data by use an electrical current to etch into Silicon a data bit and this causes Wear Levelling, whereby after so many programme erase / write cycles the Flash wears out and this could be 10,000, 100,00 or 1,000,000 writes depending on the type of Flash Storage used. Manufacturers overcome this problem in a number of ways by using sophisticated algorithms to work out how many times each cell has been used and then automatically re-map those blocks to another portion of Flash Storage.
There are three types of Wear Levelling:
- No Wear Levelling – Nothing is done with the cells and it wears out
- Dynamic Wear Levelling – Data is written evenly across the whole of the Flash
- Static Wear Levelling – Works out how many times a cell has been written and dynamically moves it.
If you want to know more about Flash Wear, please visit this site http://www.radio-electronics.com/info/data/semicond/memory/flash-wear-reliability-lifetime.php
Essential Flash Storage Checklist
When considering flash storage the features a flash vendor offers might not be deliverable to you i.e. network performance, host controllers, application issues etc. So below is a simple checklist to get you started.
- Is your storage vendor able to provide a “Proof of Concept” for 30 days? This way you should be able to determine if it works in your environment without the cost of a whole new computer system and network purchase.
- How long do they warrant the flash storage? As explained above all flash suffers from wear and you need to ensure your warranty covers this, based on your usage.
- Can they provide future proofing? Flash storage whilst isn’t as yet as affordable as spinning disks. Nonetheless, this will be an investment you are going to have for a while and in order to maximise the investment, you may need to upgrade during the product life-cycle. Are the controllers upgrade-able to newer storage interfaces? Can you “mix n match” drive capacities?
- System support and maintenance – Can the system be maintained and supported once the initial maintenance contract has expired and at what increased cost? This has been a bug bear for many companies over the years as system that is 3 years old suddenly becomes outlandishly expensive to maintain on the 37th month and you are forced to look at upgrading or look at alternatives. You might want to seat the asset for another couple of years in order to get a good ROI.
- Do they provide a “Capacity or Performance” guarantee? Your storage vendor should be saying for your environment we guarantee our storage will deliver “X” performance and “Y” capacity, this should be provided in writing. If the capacity isn’t enough and you have a guarantee how do they intend to make up the shortfall?
- How is performance provided? So in order for your to see i.e. 200,000 IOPS do you need to purchase a fully configured system or does it provide this figure as a starting block or are the provided figures based on realistic workloads or theoretical test lab results.
- Under what load and latency is performance delivered? There is no point in spending good money if the storage you are buying can only deliver the performance you need at 50% load, how does performance drop off hereafter? Latency is just as important when looking at flash storage your applications might need 1 ms response, but this can only be delivered at 30% load.
- Is the system completely resilient and redundant? This is likely to be a major investment and as such needs to be the most reliable and performing. Are all components easy to replace, extra controllers, PSU’s, backplanes, redundant data paths etc. How is performance affected if a controller fails?
- How easy is it to manage? Gone are the days where storage systems took weeks to install and required tweaking over weeks or months. Nowadays it should take no more than 2 days from opening the box to running your application. Software wizards should be available for you to easily and efficiently get your flash storage up and running. What sort of monitoring and management is provided?
- Can your flash storage scale? We already know that this is a long term investment, therefore we do not want to be in a situation 3 years down the road having to go cap in hand for more money because we can’t increase capacity or performance and we need to look at alternatives.
- How do they achieve the storage capacities quoted? One word “deduplication“, in order to deliver the quoted storage capacities all Flash storage vendors use deduplication to provide realistic achievable storage capacities. Typically these could be 5:1 or higher depending on the type of workload and application.
- Invest in infrastructure. A flash storage array will deliver super fast performance, but in order for the whole organisation to benefit, networks, host connectivity and servers need to be upgraded.
What can Flash Storage do for business?
Introduce flash storage to your business and see immediate results. Putting an SSD into an old laptop will see boot times drop from minutes to seconds and this is exactly what you will see with flash. It greatly decreases response times, writes times and read times for all applications. It should enhance existing applications even when being used as a type of cache to existing hdd’s. It’s a bit like writing 1GB of data to 1.44MB floppy disks or writing the same 1GB to USB!
Should you invest in Flash Storage?
If you are serious about future proofing your business for the next 5-10 years then I would have to say “Flash storage should have a part to play”. Yes, it is more expensive than spinning disks, but that price is easily offset by the dramatic performance gains for applications and operating systems, energy savings and overall a fantastic ROI. Flash storage should be your top storage tier and spinning disk used for backup/archiving and general purpose storage. Look for a Flash storage vendor that will allow you to “Pay As You Grow”, this essentially allows you to purchase a solution based on your business requirements for the next 1-2 years, after this time you might want to expand for capacity or performance. Adding a tray of drives or extra controllers, shouldn’t mean excessive downtime or service charges, the flash storage should adjust itself automatically with a few simple clicks.
How can we help?
With our extensive knowledge and vendor relationships, we will be able to provide a complete flash storage solution that fits your requirements and enables your business to flourish. Call us on 01256 331614 for advice and assistance, alternatively, email us Send Mail. Thank you for visiting our site.